1. Field of the Invention
The invention relates to an image processing apparatus for, particularly, dividing an input image into a character area, an area of a figure, a table, or the like in an electronic apparatus such as an OCR (optical character recognizing) apparatus, copying apparatus, facsimile apparatus, or the like.
2. Related Background Art
In a conventional image processing apparatus, there is an apparatus using a run length analyzing method as area dividing means whereby a distribution of run lengths is examined and a character area, a figure area, or the like is divided in accordance with a length of a white run or a black run. Another apparatus uses a spectrum analyzing method whereby a Fourier spectrum of an input image is analyzed and the input image is divided into various kinds of areas. Yet another apparatus uses a projection analyzing method whereby projections (histograms) in the vertical and horizontal directions are alternately repeatedly obtained and the area is divided from the information of a peripheral portion as disclosed in JP-A-1-15889.
The above conventional techniques, however, have problems such that it takes an extremely long time for arithmetic operating processes. Further, processes are executed to the pixels of an image, so that a memory area increases significantly, and a dividing precision of a complicated area construction to the image is low.
In the conventional image processing apparatus, as an area dividing means, a method is used whereby a discrimination regarding whether an area is a table or another area is made on the basis of a ratio of the area of a circumscribed rectangle and the number of pixels, and the area is divided on the basis of the result of the discrimination.
The above conventional technique, however, has a problem such as in the case where a separator or the like (modified separator) formed by complicated polygonal lines is handled as one area. When the number of pixels for the area of the circumscribed rectangle increases, such an area are erroneously recognized as a table area and a dividing precision of the area decreases.
In the conventional image processing apparatus, in the case where the attributes (character, figure, table, etc.) of the divided area are erroneously discriminated, the area data which was erroneously discriminated is eliminated and a correct area frame is newly designated by a manual operation of the operator.
In a conventional technique such that the correction of the divided area is executed by a manual operation of the operator, in the case where a plurality of erroneous divided areas exist, there is a problem such that a burden on the operator increases and a long time is needed as a ratio to the processing time of the whole image processes.
In such a type of well-known image processing apparatuses, in the case where the image area was erroneously divided, area data of the erroneous area is eliminated and the operator newly designates the correct area frame by frame using a pointing device or the like.
The above conventional technique, however, has problems such that in case of a complicated area construction, a burden of the operation of the operator increases, it takes an extremely long time as a ratio to the processing time of the whole image processes.